Send the link below via email or IMCopy
Present to your audienceStart remote presentation
- Invited audience members will follow you as you navigate and present
- People invited to a presentation do not need a Prezi account
- This link expires 10 minutes after you close the presentation
- A maximum of 30 users can follow your presentation
- Learn more about this feature in our knowledge base article
Preview: The Cosmic Landscape
Transcript of Preview: The Cosmic Landscape
The Cosmic Landscape
Astronomy is the study of the heavens, the realm extending from beyond the Earth's Atmosphere to the most distant reaches of the Universe.
Before we dive into the cosmos, however, let's take a brief tour of this landscape to become familiar with its features and gain appreciation of its scale.
Preview: The Cosmic Landscape
Planet Earth, Our Home
Even so, it influences how we see the rest of the universe because it is our base view.
Although we think of Earth as huge, it is actually one of the smallest bodies in the cosmic landscape.
Astronomers use knowledge of Earth as a guide to how other planets work.
For example, the heat which creates motion within Earth cause the planet's crust to move and buckle at the surface. The same sort of heat deep in its core generate magnetic forces at the poles and in the atmosphere.
We can use these forces as examples of processes on other planets.
For example, we find landscapes on Venus and Mars that bear evidence of many of the same processes that shape our planet.
The Moon, our nearest neighbor in Space
The moon orbits the Earth about a quarter million miles (384,000) km away.
The Moon is held in tow by Earth's gravity, and is only about one-quarter the diameter of the Earth.
It is also only about 1/80 the mass of Earth.
The differences in size and mass explain in part why the Earth and Moon have such different surfaces and characteristics.
Without the Earth's mass, the Moon was not able to retain an atmosphere. The Moon's core also cooled much more quickly, so there are no crustal motions.
Beyond the Moon, circling the same Sun, are seven other planets.
Mercury, Venus, Mars, Jupiter and Saturn are visible to the naked eye as bright points of lights, like stars.
Unlike stars, however, the planets appear to drift slowly and regularly against the pattern of background stars. This regular motion gave the planets a special significance to people in ancient times.
The Sun, our Nearest Star
The Sun is a huge ball of gas more than 100 times the diameter of Earth and more than 300,000 times more massive.
The Sun contains about 1,000 times more matter than all of the Solar System's planets combined.
If the Sun were the size of a volleyball, the Earth would be about the size of a pinhead, and Jupiter roughly the size of a nickel.
The Sun differs from the planets in more than just size; it generates energy at its core by nuclear reactions that convert hydrogen into helium.
From the core, the energy flows to the Sun's surface, and from there it pours into space.
The Solar System
The Sun and the eight planets orbiting it form the Solar System. Other objects, such as dwarf planets, asteroids and comets, orbit the Sun as well.
Most asteroids orbit between Mars and Jupiter in the "asteroid belt," also the home of the dwarf planet Ceres.